Berry连接和曲率
物理
凝聚态物理
霍尔效应
铁磁性
磁化
缩放比例
电阻率和电导率
几何相位
量子力学
磁场
几何学
数学
作者
Daisuke Kan,Lingling Xie,Yuichi Shimakawa
出处
期刊:Physical review
日期:2021-10-11
卷期号:104 (13)
被引量:13
标识
DOI:10.1103/physrevb.104.134407
摘要
We investigate the anomalous Hall effect in perpendicularly magnetized ferrimagnet $\mathrm{Ni}{\mathrm{Co}}_{2}{\mathrm{O}}_{4}$ epitaxial films 3 to 30 nm thick. We find that the anomalous Hall conductivity ${\ensuremath{\sigma}}_{\mathrm{AHE}}$ has complex relations with the longitudinal electrical conductivity ${\ensuremath{\sigma}}_{\mathrm{xx}}$. When the ${\ensuremath{\sigma}}_{\mathrm{xx}}$ is relatively large (larger than ${10}^{3}\phantom{\rule{0.16em}{0ex}}{\mathrm{\ensuremath{\Omega}}}^{--1}\phantom{\rule{0.16em}{0ex}}\mathrm{c}{\mathrm{m}}^{--1}$), the ${\ensuremath{\sigma}}_{\mathrm{AHE}}$ is almost independent of the ${\ensuremath{\sigma}}_{\mathrm{xx}}$, but scales with the magnetization. This unique scaling behavior of ${\ensuremath{\sigma}}_{\mathrm{AHE}}$ indicates that the anomalous Hall effect is of intrinsic origin dominated by the Berry curvature of occupied electronic states. On the other hand, when the ${\ensuremath{\sigma}}_{\mathrm{xx}}$ is lowered, the scaling relation is changed to ${\ensuremath{\sigma}}_{\mathrm{AHE}}\ensuremath{\sim}{\ensuremath{\sigma}}_{\mathrm{xx}}^{1.6}$, indicating a crossover of the dominant contribution to ${\ensuremath{\sigma}}_{\mathrm{AHE}}$, from the intrinsic Berry phase to the impurity scatterings. Our results show the intrinsic contribution from Berry curvature plays a crucial role in the anomalous Hall effect in $\mathrm{Ni}{\mathrm{Co}}_{2}{\mathrm{O}}_{4}$ films.
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